| Research Abstract |
Through the investigation of three years, the approach and guidelines of managing resources in arid areas were identified. The management of water and land resources in arid areas depends largely on natural and socio-economic conditions of the local area. By the introduction of irrigation in arid areas, productive agriculture can be performed for a certain period of time. However, without appropriate and efficient management of land and water resources, the ground water level gradually increases, which in turn leads to the accumulation of salts on the land surface and the degradation of land, hampering the sustainable agricultural production. Furthermore, in arid areas water resource is the major production limiting factor, and excessive lowering of ground water level could increase water requirement and irrigation water needs. Therefore, the control of the ground water level at certain range is very important in arid areas, maintaining the delicate balance between the ground water level/water needs and salt accumulation.
In addition to the ground water level, the study made clear that salt damages are subject to minor differences of on-farm level conditions such as the adoption of appropriate plowing method, irrigation management and increased use of organic matter, which improves the soil structure.
Through the investigation of detailed parameters important for agricultural production in arid areas, and the analyses of groundwater level and water management as well as cultural practices of on-farm level (plowing, organic matter application, etc) the mechanism of salt accumulation process was identified. Case studies of California agriculture under arid conditions suggest that the rehabilitation of salinized land and sustainable agricultural production can be realized through the appropriate management of water (irrigation and drainage) and land (cultivation practices) resources.
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